Next Monday, September 25, 2017, is #mathstorytellingday! [For more info go here and here.] Celebrate by sharing a math picture book. Perhaps the The Greedy Triangle by Marilyn Burns or Otoshi’s One.  Or, in creative mood? Make up your own math stories with your students/children.  The ideas of doubling and halving make great story contexts. And this week’s #mathbookmagic selection has both!

The Book

The Lion’s Share: A Tale of Halving Cake and Eating it, Too was written and illustrated by Matthew McElligott in 2009 and published by Walker and Company.

In the Lion’s Share, a lion invites an ant and a small group of animals to a special dinner. After dinner, the lion passes a large cake to the elephant who cuts the cake in half, eats half and passes the rest to the hippo.  The hippo cuts portion passed to him in half, eats his half (which is now 1/4 of the original cake) and gives the rest to the gorilla. The pattern of halving continues with each animal cutting what they are given in half and giving the remaining half to the next.

The ant waits patiently as the others divvy up the cake until he is left with an unsharable amount. Upset he has nothing to share with the lion, the ant offers to bake the lion a cake. The other animals don’t want to be shown up by an ant.  And so the beetle offers the lion double the ant’s offer (2 cakes), the frog offers double that (4 cakes), and so on until finally the elephant must bake 256 cakes.

The Math

The Lion’s share is a tale of halving and doubling.

First, the animals continuously halve the cake. They eat half and share half.  But since the referent whole for each animal’s half is getting smaller and smaller, the ant’s half to share with the lion is a meager 1/128 of the cake.  Here is a picture of each animal’s half. The labeled section is what that animal ate.

In addition to halving the cake, the increasing amount of cakes that each animal ends up baking for the lion is an example of exponential growth pattern ( 1, 2,4, 8, 16, 32, 64, 128, 256).

This book also offers opportunities to count, multiply, and reason about fractions.  With a wide-range of mathematical concepts to explore, the Lion’s Share is great for a wide-age range of children (grades K-3 and older).

The Magic

Here are three magical ingredients we found in the Lion’s Share.

1. Exponential growth: Anytime my children are faced with situations of exponential growth they get excited. I mean the elephant has to make “256 cakes!  That’s a lot of cake.”
2. Awesome illustrations: See below for one example, here for artist’s process, here for  mathematical motivation behind the page layout and book design.    
3. Math and Story connection: I have found in many of the math picture books I’ve read that either there is no actual story associated with the math and/or the story is unconnected or artificially connected to the math. That was not the case with this book. My children enjoyed the story, were captivated by the characters, and they retold the story in their own words after we were done reading. “That’s a good story.”  My son said at the end of the book. However, he wasn’t sure about the ending.  He really wanted to see the Lion get all of his cake, not just half of the cake the ant made him. And he thought the ant got “too much cake for an ant.”  And he’s right, the ant does get a whole lot of cake in the end, or should I say, the ant ends up with the Lion’s Share of the cake. [And I only made that last connection after reflecting on my son’s observations.]

Speaking of story, enjoy #mathstorytellingday next Monday! I’d love to hear what you read. To share, go to Shared booklist   or post in the comments of this post.

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Thanks and see you next Monday! #mathbookmagic